1. Physical Landscapes in the UK
Relief of the UK
Relief of the UK can be divided into uplands and lowlands. Each have their own characteristics.
Key
Lowlands
Uplands
Areas +600m: Peaks and ridges cold, misty and snow common.
i.e. Scotland
Types of Erosion
The break down and transport of rocks – smooth, round and sorted.
Attrition
Rocks that bash together to become smooth/smaller.
Solution
A chemical reaction that dissolves rocks.
Abrasion
Rocks hurled at the base of a cliff to break pieces apart or scraped against the banks and bed of a river.
Hydraulic Action
Water enters cracks in the cliff, or river bank, air compresses, causing the crack to expand.
Types of Transportation
A natural process by which eroded material is carried/transported.
Solution
Minerals dissolve in water and are carried along.
Suspension
Sediment is carried along in the flow of the water.
Saltation
Pebbles that bounce along the sea/river bed.
Traction
Boulders that roll along a river/sea bed by the force of the flowing water.
Mass Movement
A large movement of soil and rock debris that moves down slopes in response to the pull of gravity in a vertical direction.
Rock slides
occur when
there is a
failure along
the bedding
plane.
Slumping occurs when there is
a downward rotation of
sections of cliff. Often
occur after heavy rain.
Rockfall is the rapid free fall
of rock from a steep cliff
face because of gravity.
Areas -200m: Flat or rolling hills. Warmer weather.
i.e. Fens
Formation of Coastal Spits - Deposition
Swash moves up the beach at the angle of the prevailing wind.
Backwash moves down the beach at 90° to coastline, due to gravity.
Zigzag movement (Longshore Drift) transports material along beach.
Deposition causes beach to extend, until reaching a river estuary.
Change in prevailing wind direction forms a hook.
Sheltered area behind spit encourages deposition, salt marsh forms.
Types of Weathering
Weathering is the breakdown of rocks where they are.
Biological
Breakdown of rock by plants and animals e.g. roots pushing rocks apart.
Mechanical
Breakdown of rock without changing its chemical composition e.g. freeze thaw
Example: Spurn Head, Holderness Coast.
What is Deposition?
When the sea or river loses energy, it drops the sand, rock particles and pebbles it has been carrying. This is called deposition. Heaviest material is deposited first.
Formation of Bays and Headlands
Waves attack the coastline.
Softer rock is eroded by the sea quicker forming a bay, calm area cases deposition.
More resistant rock is left jutting out into the sea. This is a headland and is now more vulnerable to erosion.
Bay
Unit 1c
Soft rock
Physical Landscapes in the UK
Hard rock
Headland
How do waves form?
Waves are created by wind blowing over the surface of the sea. As the wind blows over the sea, friction is created - producing a swell in the water.
Mechanical Weathering Example: Freeze-thaw weathering
Stage One
Water seeps into cracks and fractures in the rock.
Stage Two
When the water freezes, it expands about 9%. This wedges apart the rock.
Stage Three
With repeated freeze-thaw cycles, the rock breaks off.
Formation of Coastal Stack
Hydraulic action widens cracks in the cliff face over time.
Abrasion forms a wave cut notch between high tide and low tide.
Further abrasion widens the wave cut notch to from a cave.
Caves from both sides of the headland break through to form an arch.
Weather above/erosion below –arch collapses leaving stack.
Further weathering and erosion eaves a stump.
Example: Old Harry Rocks, Dorset
Why do waves break? 1
Waves start out at sea. 2
As waves approaches the shore, friction slows the base. 3
This causes the orbit to become elliptical. 4
Until the top of the wave breaks over.
Size of waves
Affected by:
Fetch how far the wave has travelled
Strength of the wind.
How long the wind has been blowing for.
Types of Waves
Constructive Waves
Destructive Waves
This wave has a swash that is stronger than the backwash. This therefore builds up the coast.
This wave has a backwash that is stronger than the swash. This therefore erodes the coast.

2. Hydrographs and River Discharge
Coastal Defences
Hard Engineering Defences
Groynes
Wood barriers prevent longshore drift, so the beach can build up.
Beach still accessible.
No deposition further down coast = erodes faster.
Sea Walls
Concrete walls break up the energy of the wave . Has a lip to stop waves going over.
Long life span
Protects from flooding
Curved shape encourages erosion of beach deposits.
Gabions or Rip Rap
Cages of rocks/boulders absorb the waves energy, protecting the cliff behind.
Cheap
Local material can be used to look less strange.
Will need replacing.
Soft Engineering Defences
Beach Nourishment
Beaches built up with sand, so waves have to travel further before eroding cliffs.
Beach for tourists.
Storms = need replacing.
Offshore dredging damages seabed.
Managed Retreat
Low value areas of the coast are left to flood & erode.
Reduce flood risk
Creates wildlife habitats.
Compensation for land.
Water Cycle Key Terms
Precipitation
Moisture falling from clouds as rain, snow or hail.
Interception
Vegetation prevents water reaching the ground.
Surface Runoff
Water flowing over the surface of the land into rivers
Infiltration
Water absorbed into the soil from the ground.
Transpiration
Water lost through leaves of plants.
Hydrographs and River Discharge
River discharge is the volume of water that flows in a river. Hydrographs who discharge at a certain point in a river changes over time in relation to rainfall
1. Peak discharge is the discharge in a period of time.
2. Lag time is the delay between peak rainfall and peak discharge.
3. Rising limb is the increase in river discharge.
4. Falling limb is the decrease in river discharge to normal level.
Upper Course of a River
Near the source, the river flows over steep gradient from the hill/mountains. This gives the river a lot of energy, so it will erode the riverbed vertically to form narrow valleys.
River Management Schemes
Soft Engineering
Hard Engineering
Afforestation – plant trees to soak up rainwater, reduces flood risk.
Demountable Flood Barriers put in place when warning raised.
Managed Flooding – naturally let areas flood, protect settlements.
Straightening Channel – increases velocity to remove flood water.
Artificial Levees – heightens river so flood water is contained.
Deepening or widening river to increase capacity for a flood.
Formation of a Waterfall
1) River flows over alternative types of rocks.
2) River erodes soft rock faster creating a step.
3) Further hydraulic action/abrasion form a plunge pool beneath.
4) Hard rock above is undercut leaving cap rock which collapses providing more material for erosion.
5) Waterfall retreats leaving steep sided gorge.
Physical and Human Causes of Flooding.
Physical: Prolong & heavy rainfall
Long periods of rain causes soil to become saturated leading runoff.
Physical: Geology
Impermeable rocks causes surface runoff to increase river discharge.
Physical: Relief
Steep-sided valleys channels water to flow quickly into rivers causing greater discharge.
Human: Land Use
Tarmac and concrete are impermeable. This prevents infiltration & causes surface runoff.
Middle Course of a River
Here the gradient get gentler, so the water has less energy and moves more slowly. The river will begin to erode laterally making the river wider.
Case Study: Mappleton
Location and Background
The Holderness coast is in the north east of England. This is one of the most vulnerable coastlines in the world and it retreats at a rate of one to two metres every year.
The village of Mappleton, perched on a cliff top on the Holderness coast, has approximately 50 properties. Due to the erosion of the cliffs, the village is under threat.
Geomorphic Processes
-The problem is caused by: Strong prevailing winds creating longshore drift that moves material south along the coastline.
The cliffs are made of a soft boulder clay - erodes quickly, especially when saturated.
Management
-In 1991, the decision was taken to protect Mappleton - cost £2 million, involving two types of hard engineering - placing rock armour along the base of the cliff and building two rock groynes.
Mappleton and the cliffs are no longer at great risk from erosion.
The rock groynes have stopped beach material being moved south from Mappleton along the coast. However, this has increased erosion south of Mappleton. Benefits in one area might have a negative effect on another.
The increased threat of sea level rise due to climate change, means that other places will need to consider the sustainability of coastal defence strategies for the future.
Case Study - Boscastle flood August 16th 2004
Boscastle is a small village in Cornwall. It has a permanent population of under % of jobs in the village are linked to tourism.
Causes of flood - 5 hours of heavy rain (3 inches in 1 hour), Impermeable rock, steep valley sides, thin soils limit vegetation. Buildings narrowing river channel. Narrow bridges trapped debris.
Effects of flood homes and 25 businesses
damaged. 75 cars and 8 boats washed away. 150 people had to be rescued. Damage cost £15 million.
Responses to flood - Scheme cost £4.6 million. Beds of rivers lowered and channels widened. Bridges widened. Car park raised. Trees removed from near river.
Formation of Ox-bow Lakes
Step 1
Step 2
Erosion of outer bank forms river cliff. Deposition inner bank forms slip off slope.
Further hydraulic action and abrasion of outer banks, neck gets smaller.
Step 3
Step 4
Erosion breaks through neck, so river takes the fastest route, redirecting flow
Evaporation and deposition cuts off main channel leaving an oxbow lake.
Case Study (Long Profile): The River Severn
Location and Background
The source of the River Severn is in moorland in mid-Wales. The area receives excessive rainfall due to depressions from the Atlantic. The Severn swiftly grows and forms a V-shaped valley. The river transports a large load, which allows rapid erosion to take place. Waterfalls and gorges have been formed in the upper course. As the gradient decreases, meanders and oxbow lakes can be found. As the river nears the lower course, flooding is a threat.
Lower Course of a River
Near the river’s mouth, the river widens further and becomes flatter. Material transported is deposited.
Formation of Floodplains and levees
When a river floods, fine silt/alluvium is deposited on the valley floor. Closer to the river’s banks, the heavier materials build up to form natural levees.
Nutrient rich soil makes it ideal for farming.
Flat land for building houses.
River Management
Hard Engineering: dams and reservoirs, channel straightening, flood relief channels
Soft Engineering: flood warnings, preparation, floodplain zoning, planting trees (afforestation), river restoration.